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25th Micro-mineral Symposium 2007

Last Updated: 6th Jan 2008

25th Micro-mineral Symposium 2007

Carole Davies



Our micro-mineral group is 25 years old this year – so this symposium was a birthday special. The Australian Mineralogical Societies Annual Seminar was held immediately after our symposium at the same venue so this also helped to make it a special occasion. Te Rau Aroha Camp at Waihi Beach provided large enough facilities to accommodate all our symposium and seminar needs. Friday evening was the official start of the symposium and saw 44 people gather for a sociable wine and cheese get-together.


Competition judging
The camp gym became the main hub of activity with microscope lights running hot and rock breakers performing at a cracking pace. Giveaway tables were swamped with material, and donated exotic specimens were divvied out all weekend.

Our micro-mineral competitions on Saturday provided the usual tough decisions with 2 re-votes required for equal winners. Also this year we had a mineral photo competition in either micro size or macro camera setting for a New Zealand specimen.

The competition trophies were presented to the winners later in the evening.

The Stan Rowe Memorial Trophy for best overseas specimen was won by Judy Rowe for a beautiful acicular cluster of golden calcite crystals in a cavity lined with chabazite from Bundoora, Victoria, Australia.

The Tetrahedron Trophy for best NZ specimen went to Pat Byrne for a perfect ferrierite spray from Thames in the Coromandel Peninsula.

Second place went to Carole Davies for an intriguing cluster of double ended quartz crystals on a thin stalk – from Muzzle Station, South Island.

David McDonald won the trophy for the best, last field trip specimen with some nice phillipsite crystals from View Hill Quarry near Loburn, South Island.

Mat Singleton won the photo competition with an eye-catching picture of a 2mm Aragonite spray from Aranga Quarry, Northland

Our 25th birthday cake was cut after dinner – it took the shape of a bright green hill with a mine and 3 trucks of ore emerging from it. This was crafted by Rod Martin’s daughter Brooke – great job, thank you Brooke – and it also tasted delicious.

Our first field trip took us to Henderson’s Quarry, Mt Ngongotaha, Rotorua on Sunday. Most of the known minerals from this quarry were found including osumilite and mullite by a few lucky people. The more common ones collected were fayalite, pseudobrookite, phlogopite, edenite, hematite, ferri-edenite, quartz and tridymite.

Many of these crystals occurred in numerous lithophysae formations.

Later that evening we were entertained by Steve Sorrell who showed us the presentation that he gave at Tucson on Australian minerals, and also gave us an interesting talk on Tasmanian minerals.

The main event on Monday as always was our auction to help finance future symposiums. There was an amazing array of donated specimens – some of them of considerable value, which made the auction both exciting and interesting. Among the more notable donations were 3 type locality wairakite specimens from GNS, a range of mainly Arizona minerals (including some gold specimens) from Mark Ascher and other members of the Tucson Gem and Mineral Society Micromount Group (a number of these were also circulated in the giveaway boxes), a selection of English minerals from Harry and Christine Critchley and a selection of hand made glass jewellery by Ted Weardon. We thank everyone very much for their generous donations which gave us an auction total of over $2500. Audrey Young also donated a range of material that was keenly shared by all.

We had our symposium evaluation in the afternoon – and also decided that the 2009 symposium will be held either in Northland or near Auckland on the west coast. The Australian seminar officially started on this Monday evening with registration, wine and nibbles.


White Is crater
Our next scheduled field trip was to White Island volcano on Tuesday. Despite windy conditions the trip was still planned so we all boarded the boat at Whakatane. About two hours later we reached the shelter of the steaming island and were ferried ashore in an inflatable. We were guided round the inside of the crater and marvelled at all the thermal activity going on. Lots of steam vents with sulphur crystals – in fact the entire high rim of the crater contained numerous steam vents. An acidic lake of zero pH was billowing large puffs of steam and needless to say we didn’t venture too close to the crumbling edges. This lake periodically fills and drains from underground activity. Yellow and white fluffy sulphate crystals lined the sides of banks and drains along the route.

Group photo
We examined the ruins of the old sulphur factory that was wiped out by a lahar in 1914 with the loss of ten lives, then we headed back to the mainland. We encountered 25 – 30 knot winds all the way back and the boat spent more time going through waves than over them - consequently many brown paper bags and towels surfaced - but a great trip.

Next day we all enjoyed a very calm trip to Karangahake Gorge to explore the site of the old Victoria Gold Battery at Waikino. This used to be the largest quartz crushing plant in Australasia from 1897 – 1954. The plant consisted of 200 stamps, crushing up to 800 tonnes of ore a day from the Martha Gold Mine at Waihi. Before 1900 the ore was roasted in huge brick kilns set into the ground and dropped down chutes into small railway wagons underground. These kilns have now been restored and we were able to walk the rail tunnel beneath. We also looked through the museum in the old transformer house – well worth a visit. On the way out we examined scattered fragments of the slag from the ore roasting which contains small (up to 3mm) ‘Dore’ balls of 75% silver.

Tourist train at Victoria Battery


Nearby we visited the type locality for Owharoaite (a lenticular ignimbrite) in a rock face beside the road.

Owharoa quarry face


Further along the river at Waitawheta Gorge we viewed the sites of several old gold mines via a walkway developed from previous mine rail tracks.

Mt Karangahake is riddled with old gold mines which were in operation from 1882 till 1944. Currently, Heritage Gold New Zealand Ltd is undertaking mine refurbishing and drilling to confirm and expand the gold-silver resource.

On the Saturday after the Seminar we were treated to a guided trip by Trevor Hosking into the Lake Rotokawa thermal area – closed to the general public. We were warned not to wander off the track as there is unstable ground with collapse craters. As a further precaution, leaders wore lead acetate tapes to warn of H2S presence.

Trevor showed us magnificent dense growths of delicate sulphur crystals in hot steaming vents and pointed out low lying areas where small dead animals and birds could be seen – having met their fate from CO2 poisoning. We had lunch beside the main lake and walked around an adjoining hydrothermal area of bubbling, blue, mineralised water surrounded by siliceous sinter, rich in gold silver and arsenic. These waters appeared to be draining and filling through subterranean channels, creating different levels within this site. We were then taken to an old mined area where we collected beautiful but very fragile sulphur crystals by digging into banks. A fascinating area - many thanks to Trevor.

This was yet another enjoyable symposium – Rod Martin did an absolutely wonderful job of organising this special double event – and thanks also to those people who helped everything to tick along so well. We look forward to the next micro-mineral symposium at Bannockburn, Central Otago.


30th Joint Annual Seminar of the Australian Mineralogical Societies, 2007

Rod Martin



The Australian Mineralogical Societies Annual Seminar was held on the Thursday and Friday following the field trips and was attended by 41 people. For most of the NZ'ers this was the first Joint Seminar they had attended and we hope that they will now consider making the trip across the Tasman to the meetings in other states. Unfortunately two of our speakers had to pull out at short notice but they did provide their presentations and notes so that the talks could still be given. Of particular note was the presentation by Mat and Carole on Aranga – this was their first presentation at a Seminar or Conference and was extremely well constructed and delivered, we look forward to more of the same from them.

Thursday evening was also the Seminar dinner at the Waihi Beach RSA and a magnificent spread was provided in a stunning location on the top of a cliff looking out to Mayor Island. Brooke also provided a decorated cake for this 30th meeting in the form of an open book with a map of Australia and this led to one of the few glitches when it was discovered that Tasmania was missing. Peace was restored when the missing island was found to be in the packing box having fallen off in transit. Once more we thank Brooke for her efforts in producing two wonderful cakes.

Seminar group photo

Friday saw the final two talks followed by the AGM of the Joint Seminar and at this meeting it was agreed that the next meeting would be in Tasmania in early Nov 2008 (probably at Queenstown) and that the term Australia in the Joint Seminar title would be replaced by Australasian to reflect NZ’s presence.

After a short break for morning tea everyone was quickly into buying and selling mode with a wide range of material available. Larry Queen had a range gold nuggets from PNG and Audrey Young was in attendance with a number of trays of mainly Coromandel material. Unfortunately we only remembered about the group photo after a few had left for Hot Water Beach and other places of interest.
The next Joint Seminar meeting in NZ is likely to occur in 6 or 7 years time and will probably run under the NZGeMS (NZ Geochemical and Mineralogical Society) umbrella. The time of year and exact venue will be decided later but it is hoped that it can be run in the Nelson/Marlborough region

Convenor notes and finances
Rod Martin



Both meetings went very smoothly thanks to the assistance of all the members of the Northern Region Mineral Group but special thanks should go to Pat Byrne and also to Phil and Sue Ericksson, all of whom stepped up whenever they saw anything that needed doing and made my job as convenor a lot easier.


As previously mentioned the good turnout at the Symposium auction and the high quality of donations meant that we raised $2,529 to add to the carried over balance of $3,031.74 transferred from the 2006 Symposium at Christchurch.

Once more I’d like to thank everyone for their assistance, especially those who gave talks (both formal and the informal evening ones) and chaired sessions at the Seminar.

Rod




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